FIELD OF DISCLOSURE
[0001] Embodiments disclosed herein relate generally to heat exchanger systems. More particularly,
embodiments disclosed herein relate to vertical rod baffle heat exchangers for reaction
heat removal.
BACKGROUND
[0002] Rod baffle heat exchangers were created in 1970 by Philips Petroleum Company to eliminate
flow-induced vibrations in a plate baffle heat exchanger. Rod baffle heat exchangers
are shell and tube type heat exchangers utilizing rod baffles to support the tubes
and secure them against vibrations. Additionally, rod baffles can be used to correct
shell-side flow distributions and to create a more turbulent shell-side flow. The
term "baffle" refers to an annular ring in which the ends of a plurality of support
rods are connected; hence the term "rod baffle". Examples of rod baffle heat exchangers
may be found in, for example,
U.S. Patent No. 5,642,778 and Chinese Patent No.
104197751, which are incorporated herein by reference.
[0003] As shown in Figure 1, a conventional rod baffle heat exchanger, such as a shell and
tube heat exchanger 10, may include a rod baffle tube bundle 12 surrounded by a shell
14. Tubes 28 in the tube bundle 12 are supported by a plurality of rod baffle assemblies
16, 18, 20, and 22. One fluid enters the shell-side of the shell and tube heat exchanger
10 through an inlet 26 and after heat exchange with the fluid in tubes 28 leaves the
shell-side via outlet 30. The fluid flowing through the tube side of the heat exchanger
enters the end cap 38 of the heat exchanger via inlet 32 and leaves the end cap 44
of the heat exchanger via outlet 34. Thus, fluid flows from end chamber 36, which
is defined by end cap 38 of the heat exchanger 10 and tube sheet 40, through the tubes
28 and into the opposite end chamber 42, which is similarly defined by the end cap
44 and the other tube sheet 46.
SUMMARY
[0004] This summary is provided to introduce a selection of concepts that are further described
below in the detailed description. This summary is not intended to identify key or
essential features of the claimed subject matter, nor is it intended to be used as
an aid in limiting the scope of the claimed subject matter.
[0005] In one aspect, the embodiments disclosed herein relate to a vertical rod baffle heat
exchanger that may be used for heat removal, condensation operations, electricity
generation, petrochemical plants, waste heat recovery, and other industrial applications.
The vertical rod baffle heat exchanger may include a shell; a tube-sheet; a tube bundle
having a plurality of heat exchange tubes extending in an axial direction, wherein
the tube bundle is a U-tube bundle may have a U-bend in the plurality of heat exchange
tubes; six or more longitudinal partition plates, wherein at least one longitudinal
partition plate is a notched longitudinal partition plate; and a plurality of rod
baffle rings provided along an axial length of the plurality of heat exchange tubes,
wherein the plurality of rod baffle rings may have lateral rod baffles and longitudinal
rod baffles. The lateral rod baffles and the longitudinal rod baffles may pass through
gaps between every two adjacent tubes of plurality of heat exchange tubes, and the
lateral rod baffles may pass through openings in the notched longitudinal partition
plate. The notched longitudinal partition plates may extend a length in a radial direction
to have a notched end of the notched longitudinal partition plates within the U-tube
bundle.
[0006] In one or more aspects, the vertical rod baffle heat exchanger may further include
a plurality of support bars arranged on a circumference of the shell adapted to fix
the tube bundle and be a slideway for the plurality of rod baffle rings. The plurality
of support bars may be spaced apart from each other and rotated in 90-degree increments
around a circumference of the plurality of rod baffle rings. A non-condensable gas
outlet may be provided at a similar level close to the tube-sheet on the shell as
a vapor inlet. A liquid seal cylindrical section may be provided close to an elbow
section on the shell side. An impingement plate may be provided in the shell to distribute
incoming vapor from the inlet.
[0007] In some aspects, the plurality of rod baffle rings may have a set of four rod baffle
rings: a first rod baffle ring having a plurality of lateral rod baffles extending
from an inner surface of the first rod baffle ring, a second rod baffle ring having
a plurality of longitudinal rod baffles extending from an inner surface of the second
rod baffle ring, a third rod baffle ring having a plurality of lateral rod baffles
extending from an inner surface of the third rod baffle ring, and a fourth rod baffle
ring having a plurality of longitudinal rod baffles extending from an inner surface
of the fourth rod baffle ring. The vertical rod baffle heat exchanger may include
at least four sets of four rod baffle rings. Additionally, a fifth set of four rod
baffle rings may include two of the first rod baffle rings, the third rod baffle ring,
and the fourth rod baffle ring. Each of the plurality of rod baffle rings may be evenly
spaced a distance from an adjacent rod baffle across a length of the U-tube bundle.
Each of the six or more longitudinal partition plates may be a notched longitudinal
partition plate. A width of each of the longitudinal partition plates may be between
3 to 9 millimeters.
[0008] In yet another aspect, a distance between the longitudinal partition plates and a
length of the notched longitudinal partition plates may varied. A distance between
a first longitudinal partition plate and a second longitudinal partition plate may
be greater than a distance between the second longitudinal partition plate and a third
longitudinal partition plate. The distance between the second longitudinal partition
plate and the third longitudinal partition plate may be greater than a distance between
the third longitudinal partition plate and a fourth longitudinal partition plate.
The distance between the third longitudinal partition plate and the fourth longitudinal
partition plate may be greater than a distance between the fourth longitudinal partition
plate and a fifth longitudinal partition plate. The distance between the fourth longitudinal
partition plate and the fifth longitudinal partition plate may be greater than a distance
between the fifth longitudinal partition plate and a sixth longitudinal partition
plate. The notched end of each notched longitudinal partition plate may be a vertical
distance from the shell. The vertical distance of the notched longitudinal partition
plates may progressively decrease from the first longitudinal partition plate to the
sixth longitudinal partition plate.
[0009] Other aspects and advantages will be apparent from the following description and
the appended claims.
BRIEF DESCRIPTION OF DRAWINGS
[0010]
Figure 1 illustrates a side elevation view of a shell and tube heat exchanger in accordance
with the prior art.
Figure 2 illustrates a top view of a rod baffle heat exchanger in accordance with
one or more embodiments of the present disclosure.
Figure 3 illustrates a perspective view of a plurality of rod baffle rings of a rod
baffle heat exchanger in accordance with one or more embodiments of the present disclosure.
Figure 4 illustrates a partial close-up top view of a plurality of tubes of a rod
baffle heat exchanger in accordance with one or more embodiments of the present disclosure.
Figure 5 illustrates a partial view of a rod baffle heat exchanger in accordance with
one or more embodiments of the present disclosure.
DETAILED DESCRIPTION
[0011] Embodiments of the present disclosure are described below in detail with reference
to the accompanying figures. Like elements in the various figures may be denoted by
like reference numerals for consistency. Further, in the following detailed description,
numerous specific details are set forth in order to provide a more thorough understanding
of the claimed subject matter. However, it will be apparent to one having ordinary
skill in the art that the embodiments described may be practiced without these specific
details. In other instances, well-known features have not been described in detail
to avoid unnecessarily complicating the description. As used herein, the term "coupled"
or "coupled to" or "connected" or "connected to" may indicate establishing either
a direct or indirect connection and is not limited to either unless expressly referenced
as such. As used herein, fluids may refer to slurries, liquids, gases, and/or mixtures
thereof. Wherever possible, like or identical reference numerals are used in the figures
to identify common or the same elements. The figures are not necessarily to scale,
and certain features and certain views of the figures may be shown exaggerated in
scale for purposes of clarification.
[0012] In one aspect, embodiments disclosed herein relate to a rod baffle heat exchanger
for heat removal, condensation operations, electricity generation, petrochemical plants,
waste heat recovery, and other industrial applications. The rod baffle heat exchanger
may also be interchangeably referred to as a rod baffle condenser in the present disclosure.
Additionally, the rod baffle heat exchanger may incorporate vertical baffles with
vertical partition plates. The rod baffle heat exchanger may aid in the removal of
polymerization heat in a cool loop. Further, the rod baffle heat exchanger may allow
for a higher condensation efficiency compared to conventional condensers.
[0013] Conventional rod baffle heat exchangers in industrial applications are typically
exceptionally large and heavy due to horizontal arrangement. Additionally, conventional
vertical rod baffle heat exchangers use small and shorter longitudinal baffle plates.
Conventional vertical rod baffle heat exchangers are not sufficient for the increased
size and capacity of modern polymerization reactors. For example, conventional vertical
rod baffle heat exchangers, when increased for size and capacity, may cause shutdowns
due to too low of a liquid level and subsequently a short cut of vapor flow.
[0014] Accordingly, one or more embodiments in the present disclosure may be used to overcome
such challenges as well as provide additional advantages over conventional rod baffle
heat exchangers, as will be apparent to one of ordinary skill. In one or more embodiments,
the rod baffle heat exchanger may increase a gas velocity around tubes in the rod
baffle heat exchanger and increase the operational range with regards to heat exchange
coefficient. Rod baffle heat exchangers, according to embodiments herein, may include
prolonged baffle plates, allowing lower liquid levels to enlarge the operation range
of the polymerization process. In one or more embodiments, the prolonged longitudinal
baffle plates may reduce a risk of plant shutdowns during unexpected changes in cooling
water temperature and allow to operate the plant with higher throughputs. The rod
baffle arrangement in the heat exchanger provides improved vibration protection by
the rod baffles being distributed more evenly. Additionally, the rod baffle heat exchangers
may increase reliability and performance over cycles of operation. Overall, the rod
baffle heat exchangers may minimize product engineering, risk associated with rod
baffle manufacture, reduction of assembly time, hardware cost reduction, and weight
and envelope reduction.
[0015] Rod baffle heat exchangers, according to embodiments herein, may include a number
of longitudinal baffle plates to increase the vapor velocities, making the heat transfer
more efficient. In a non-limiting example, the rod baffle heat exchanger may have
six longitudinal baffle plates. In one or more embodiments, support for lateral and
longitudinal rods of the rod baffle heat exchanger may be split and distributed more
evenly to improve an anti-vibration effect. Further, a length of the longitudinal
baffle plates may be increased to cover at least a full length of a U-bundle in order
to increase an operational flexibility by maintaining a liquid seal even at low levels.
[0016] In one or more embodiments, the rod baffle heat exchanger may be a vertical rod baffle
condenser with one or more prolonged longitudinal partition plates, such as six or
more prolonged longitudinal partition plates. The prolonged longitudinal partition
plates may allow a higher condensation efficiency in the vertical rod baffle condenser
by increasing the gas velocity around the tubes. In addition, the prolonged longitudinal
partition plates may increase the operational range with regards to heat exchange
coefficient by the prolonged baffle plates, which allow lower liquid levels.
[0017] Turning to Figure 2, Figures 2 shows a top view of a rod baffle heat exchanger 100
in accordance with one or more embodiments of the present disclosure. The rod baffle
heat exchanger 100 may include six or more longitudinal partition plates 101. The
six or more longitudinal partition plates 101 may be inserted within a tube bundle
102 of the rod baffle heat exchanger 100. The tube bundle 102 is surrounded by a shell
103. Additionally, a tube-sheet 119 may be provided on top of the six or more longitudinal
partition plates 101. In one or more embodiments, a distance D between the longitudinal
partition plates 101 may be varied. In a non-limiting example, the distance D between
a first longitudinal partition plate 101a and a second longitudinal partition plate
101b may be greater than the distance between the second longitudinal partition plate
101b and a third longitudinal partition plate 101c. The distance between the second
longitudinal partition plate 101b and the third longitudinal partition plate 101c
may be greater than the distance between the third longitudinal partition plate 101c
and a fourth longitudinal partition plate 101d. The distance between the third longitudinal
partition plate 101c and the fourth longitudinal partition plate 101d may be greater
than the distance between the fourth longitudinal partition plate 101d and a fifth
longitudinal partition plate 101e. The distance between the fourth longitudinal partition
plate 101d and the fifth longitudinal partition plate 101e may be greater than the
distance between the fifth longitudinal partition plate 101e and a sixth longitudinal
partition plate 101f. It is further envisioned that a width W of each of the longitudinal
partition plates 101 may have a value between 3 to 9 mm, such as 8mm.
[0018] In one or more embodiments, one or more of the six or more longitudinal partition
plates 101 may be a notched longitudinal partition plate 104 provided in the tube
bundle 102. Each of the notched longitudinal partition plates 104 may have a notched
end 105 that is a vertical distance Dn from the shell 103. Each of the notched longitudinal
partition plates 104 may have varied vertical distances Dn. The vertical distance
Dn of the notched longitudinal partition plates 104 may progressively decrease from
the first longitudinal partition plate 101a to the sixth longitudinal partition plate
101f. In a non-limiting example, the vertical distance Dn of the first longitudinal
partition plate 101a may be greater than the vertical distance of the second longitudinal
partition plate 101b. The vertical distance of the second longitudinal partition plate
101b may be greater than the vertical distance of the third longitudinal partition
plate 101c. The vertical distance of the third longitudinal partition plate 101c may
be greater than the vertical distance of the fourth longitudinal partition plate 101d.
The vertical distance of the fourth longitudinal partition plate 101d may be greater
than the vertical distance of the fifth longitudinal partition plate 101e. The vertical
distance of the fifth longitudinal partition plate 101e may be greater than the vertical
distance of the sixth longitudinal partition plate 101f. Additionally, adjacent notched
longitudinal partition plates 104 may be oriented 180 degrees such that each notched
end 105 terminates the adjacent notched longitudinal partition plates 104 in an opposite
direction from the shell 103.
[0019] Still referring to Figure 2, an outlet 107 may be provided at a similar level (circumferential
location), close to the tube-sheet 119 on the shell 103, as the inlet 108. The outlet
may be a non-condensable gas outlet and the inlet 108 may be a vapor inlet in some
embodiments. Additionally, a liquid seal cylindrical section 109 may be provided below
an elbow section 109a of the rod baffle heat exchanger 100 on the shell 103. The elbow
section 109a may be a portion of the shell 103 forming the outlet 107 and the inlet
108. Further, an impingement plate 110 may be installed in the shell 103 to distribute
incoming vapor from the inlet 108.
[0020] In some embodiments, a plurality of tubes 106 may extend in an axial direction within
the tube bundle 102 such that the six or more longitudinal partition plates 101 partition
the plurality of tubes 106 of the tube bundle 102. In one or more embodiments, the
tube bundle 102 may be a U-tube bundle such that the plurality of tubes 106 have a
bend. It is further envisioned that the notched longitudinal partition plates 104
may extend a length in a radial direction such that the notched end 105 is within
the tube bundle 102. The length of the notched longitudinal partition plates 104 may
be measured from an end attached to the shell 103 to the notched end 105. In a non-limiting
example, a minimum length of the notched longitudinal partition plates 104 is greater
than a lowest point at which a tube 106 is provided in the U-tube bundle 102.
[0021] As shown in Figure 3, in one or more embodiments, the rod baffle heat exchanger 100
may include a plurality of rod baffle rings 111, 112, 113, 114 distributed along an
axial axis Ax of the plurality of tubes (see 106 in Figure 2). For example purposes
only, Figure 3 is shown with four rod baffle rings 111, 112, 113, 114; however, the
rod baffle heat exchanger 100 may have any number rod baffle rings without departing
from the scope of the present disclosure. Additionally, a plurality of support bars
115 may be arranged on a circumference of the shell (see 103 in Figure 2), which may
be used to fix the tube bundle (see 102 in Figure 2) and function as a slideway for
the plurality of rod baffle rings 111, 112, 113, 114. In a non-limiting example, the
rod baffle heat exchanger 100 may have four support bars 115 evenly spaced such that
the support bars 115 may be in 90-degree increments around a circumference of the
plurality of rod baffle rings 111, 112, 113, 114.
[0022] In one or more embodiments, the plurality of rod baffle rings 111, 112, 113, 114
may be provided in sets of four. The plurality of rod baffle rings 111, 112, 113,
114 may be in a configuration to have each rod baffle ring rotated at 90-degrees from
an adjacent rod baffle ring. By staggering the plurality of rod baffle rings 111,
112, 113, 114 at 90 degrees back and forth, the rod baffle heat exchanger 100 may
eliminate a phenomenon of liquid accumulation and realize a high-flux flow of condensate
on the plurality of tubes (see 106 in Figure 2). In a non-limiting example, the first
rod baffle ring 111 in the set of four rod baffle rings may have a plurality of lateral
rod baffles 111a extending from an inner surface 111b of the first rod baffle ring
111. The second rod baffle ring 112 in the set of four rod baffle rings may have a
plurality of longitudinal rod baffles 112a extending from an inner surface 112b of
the second rod baffle ring 112. The third rod baffle ring 113 in the set of four rod
baffle rings may have a plurality of lateral rod baffles 113a extending from an inner
surface 113b of the third rod baffle ring 113. The fourth rod baffle ring 114 in the
set of four rod baffle rings may have a plurality of longitudinal rod baffles 114a
extending from an inner surface 114b of the fourth rod baffle ring 114.
[0023] Now referring to Figure 4, in one or more embodiments, Figure 4 shows a partial close-up
top view of the plurality of tubes 106 being spaced by the lateral rod baffles 111a,
113a of the first and third rod baffle rings 111, 113 and the longitudinal rod baffles
112a, 114a of the second and fourth rod baffle rings 112, 114.
[0024] As shown in Figure 4, the lateral rod baffles 111a, 113a pass through a gap 115 between
adjacent tubes (106) in the X axis direction. The longitudinal rod baffles 112a, 115a
pass through a gap 116 between adjacent tubes (106) in the Y axis direction. Additionally,
the lateral rod baffles 111a, 113a may also pass through openings in the notched longitudinal
partition plates (see 104 in Figure 2). By increasing a distance between the lateral
and longitudinal rods, the flow of liquid condensate in the plurality of tubes 106
may be less restricted and the support of the plurality of tubes 106 may be more evenly
distributed over the length of the plurality of tubes 106.
[0025] Now referring to Figure 5, in one or more embodiments, Figure 5 shows a partial view
of the rod baffle heat exchanger 100. As shown Figure 5, the plurality of tubes 106
may be in the tube bundle 102 such as a U-tube bundle extending a length L. One skilled
in the art will appreciate how the U-tube bundle 102 allows the plurality of tubes
106 to bend, e.g., U-bend 118, such that full length of the plurality of tubes 106
is greater than the length L of the U-tube bundle 102. This allows the rod baffle
heat exchanger 100 to have longer tubes 106 while remaining compact and decrease the
overall footprint of the rod baffle heat exchanger 100.
[0026] As shown in Figure 5, in one or more embodiments, the rod baffle heat exchanger 100
may have 4 sets of the set of four rod baffle rings 111, 112, 113, 114 as described
in Figure 3 such that there are 8 sets of the rod baffle rings with lateral rods and
8 sets of the rod baffle rings with longitudinal rods. In addition, the rod baffle
heat exchanger 100 may include a fifth set of four rod baffle rings configured with
two first rod baffle rings such that the order of rod baffle rings is 111, 111, 113,
114, accounting from a U-bend 118 in the U-tube bundle 102. Each of the rod baffle
rings 111, 112, 113, 114 may be spaced a distance Drb from an adjacent rod baffle
such the rod baffle rings 111, 112, 113, 114 are evenly spaced across the length L
of the U-tube bundle. Additionally, each of the rod baffle rings 111, 112, 113, 114
may have a thickness T such that the rod baffle rings have a uniform thickness. It
is further envisioned that a rear part 117 of the U-tube bundle may have an anti-vibration
grid structure.
[0027] While the present disclosure has been described with respect to a limited number
of embodiments, those skilled in the art, having benefit of this disclosure, will
appreciate that other embodiments may be devised which do not depart from the scope
of the disclosure as described herein. Accordingly, the scope of the disclosure should
be limited only by the attached claims.
1. A vertical rod baffle heat exchanger comprising:
a shell (103);
a tube-sheet (119);
a tube bundle (102) having a plurality of heat exchange tubes (106) extending in an
axial direction, wherein the tube bundle (102) is a U-tube bundle comprising a U-bend
in the plurality of heat exchange tubes (106);
six or more longitudinal partition plates (101), wherein at least one longitudinal
partition plate is a notched longitudinal partition plate (104); and
a plurality of rod baffle rings (111, 112, 113, 114) provided along an axial length
of the plurality of heat exchange tubes (106), wherein the plurality of rod baffle
rings have lateral rod baffles and longitudinal rod baffles,
wherein the lateral rod baffles and the longitudinal rod baffles pass through gaps
between every two adjacent tubes of plurality of heat exchange tubes, and the lateral
rod baffles pass through openings in the notched longitudinal partition plate (104),
and
wherein the notched longitudinal partition plates (104) extend a length in a radial
direction to have a notched end (105) of the notched longitudinal partition plates
within the U-tube bundle.
2. The vertical rod baffle heat exchanger according to claim 1, further comprising a
plurality of support bars (115) arranged on a circumference of the shell (103) adapted
to fix the tube bundle (102) and be a slideway for the plurality of rod baffle rings.
3. The vertical rod baffle heat exchanger according to claim 2, wherein the plurality
of support bars (115) are spaced apart from each other and rotated in 90-degree increments
around a circumference of the plurality of rod baffle rings.
4. The vertical rod baffle heat exchanger according to any one of claims 1 to 3, further
comprising a non-condensable gas outlet (107) provided at a similar level close to
the tube-sheet on the shell as a vapor inlet.
5. The vertical rod baffle heat exchanger according to claim 4, further comprising a
liquid seal cylindrical section (109) provided close to an elbow section (109a) on
the shell side.
6. The vertical rod baffle heat exchanger according to claim 4 or 5, further comprising
an impingement plate (110) provided in the shell (103) to distribute incoming vapor
from the inlet.
7. The vertical rod baffle heat exchanger according to any one of claims 1 to 6, wherein
the plurality of rod baffle rings comprises a set of four rod baffle rings:
a first rod baffle ring (111) having a plurality of lateral rod baffles (111a) extending
from an inner surface (111b) of the first rod baffle ring,
a second rod baffle ring (112) having a plurality of longitudinal rod baffles (112a)
extending from an inner surface (112b) of the second rod baffle ring,
a third rod baffle ring (113) having a plurality of lateral rod baffles (113a) extending
from an inner surface (113b) of the third rod baffle ring, and
a fourth rod baffle ring (114) having a plurality of longitudinal rod baffles (114a)
extending from an inner surface (114b) of the fourth rod baffle ring.
8. The vertical rod baffle heat exchanger according to claim 7, further comprising at
least four sets of four rod baffle rings.
9. The vertical rod baffle heat exchanger according to claim 8, further comprising a
fifth set of four rod baffle rings comprising two of the first rod baffle rings, the
third rod baffle ring, and the fourth rod baffle ring.
10. The vertical rod baffle heat exchanger according to any one of claims 1 to 9, wherein
each of the plurality of rod baffle rings (111, 112, 113, 114) are evenly spaced a
distance from an adjacent rod baffle across a length of the U-tube bundle.
11. The vertical rod baffle heat exchanger according to any one of claims 1 to 10, wherein
each of the six or more longitudinal partition plates (101) are a notched longitudinal
partition plate (104).
12. The vertical rod baffle heat exchanger according to any one of claims 1 to 11, wherein
a width of each of the longitudinal partition plates (101) is between 3 to 9 millimeters.
13. The vertical rod baffle heat exchanger according to any one of claims 1 to 12, wherein
a distance between the longitudinal partition plates (101) and a length of the notched
longitudinal partition plates (104) are varied.
14. The vertical rod baffle heat exchanger according to claim 13, wherein:
a distance between a first longitudinal partition plate (101a) and a second longitudinal
partition plate (101b) is greater than a distance between the second longitudinal
partition plate (101b) and a third longitudinal partition plate (101c),
the distance between the second longitudinal partition plate (101b) and the third
longitudinal partition plate (101c) is greater than a distance between the third longitudinal
partition plate (101c) and a fourth longitudinal partition plate (101d),
the distance between the third longitudinal partition plate (101c) and the fourth
longitudinal partition plate (101d) is greater than a distance between the fourth
longitudinal partition plate (101d) and a fifth longitudinal partition plate (101e),
and
the distance between the fourth longitudinal partition plate (101d) and the fifth
longitudinal partition plate (101e) is greater than a distance between the fifth longitudinal
partition plate 101e) and a sixth longitudinal partition plate (101f).
15. The vertical rod baffle heat exchanger according to claim 14, wherein the notched
end (105) of each notched longitudinal partition plate (104) is a vertical distance
from the shell, wherein the vertical distance of the notched longitudinal partition
plates (104) progressively decreases from the first longitudinal partition plate (101a)
to the sixth longitudinal partition plate (101f).